1. Field of the Invention
The present invention relates to a flat display unit such as a liquid crystal display unit, a plasma display unit, an electron emission display unit, or a display unit using an organic EL, and an interpolation signal generation method, more particularly to improvement of a technology which supplies color signals to color pixels.
2. Description of the Related Art
For example, video signals (color signals of R, G, B) of one system are supplied to a flat display unit into which color digital signals are input based on a clock signal (CLK). The color signals of R, G, B have the same image phase. That is, when one of color pixels is seen, an image of one point is color-decomposed, and prepared as the color signals of R, G, B.
On the other hand, when a pixel arrangement of the flat display unit is seen, three primary colors cannot be represented by one point. Therefore, R, G, B pixels are arranged in order in a scanning line (row) direction, and the arrangement of the pixels of three colors is repeated (see, e.g., Jpn. Pat. Appln. KOKAI Publication No. 5-108032).
When a relation between the three color signals and the pixel arrangement is seen from a spatial frequency, the phase of each color signal is displayed as a 120-degree shifted image. In the flat display unit, data for one horizontal scanning period is written together into the respective pixels of one row. That is, a pixel electrode portion of each pixel is charged with pixel image data corresponding to each pixel. Therefore, the above-described deviation of 120 degrees also appears as deviation of resolution of the whole image.
In this flat display unit, when the image moving in a horizontal direction is displayed in a screen, picture quality degradation occurs such as bleeding of color. This phenomenon becomes remarkable as a panel size increases.